This invention relates in general to the construction of sewing machines and in particular to a new and useful sewing machine for making edge parallel shaping seams.
A sewing machine of this type is known from U.S. Pat. No. 4,181,085 (German OS No. 28 33 634) for sewing the outer corner seam in shirt collars. In order to be able to hold the components of the shirt collar, congruently and precisely by the outer and/or corner seam, the components are placed one on top of the other, and their eventual inner sides are provided with a stiffening insert. They are then sewn together with a joining seam on three sides and turned. It is conventional to iron the collars flat on shaping plates by subjecting them to pressure and heat. The plates conform to the outside contour of the shirt collar. A machine for doing this is known from U.S. Pat. No. 4,213,547 (German OS No. 29 39 728). Since the processing time required for a satisfactory ironing for an article of clothing on these machines is very much greater than that required on modern sewing machines for making the outer corner seam, either longer downtimes for the rather expensive sewing station must be accepted, or a setup of this kind must be forgotten when the work station consists of one machine for turning and ironing and a sewing part for making the outer corner seam on shirt collars.
U.S. Pat. No. 2,311,407 teaches the use of a hem edge guide as an aid in sewing a shirt collar, which is composed of an outer collar and a neck band, to the upper edge of the body of a shirt. The guide consists of a pleating and guide fence under spring action, with a horizontal turndown flange, pivotably mounted on an extension mounted on the material pressure bar of the sewing machine so that it can swivel into a working or a resting position. The turndown flange is provided with a leading edge which is directed at an angle to the feed direction of the material. The edge, in the working position, engages the inner free edge of the lower layer of material of the neck band, which is sewn together with a stiffening insert to the upper edge of the body of the shirt, and folded inward through 180.degree. so that the edge is guided in a flattened position to the point where the stitches are made. At this location the uppermost layer of material in the neck band, together with the lower layer of material and the stiffening insert, is sewn by a second seam to the body of the shirt. This eliminates pre-ironing.
This known pleating and guide fence, however, can only be moved into the operating position when the initial area of the neck band has been appropriately turned and sewn by hand because the side edge of the neck band is closed. Before reaching the end of the seam, the pleating fence must be swung back from the working position to the resting position because of the closed side edge of the neck band, and the material must be turned over by hand for the remainder of the seam.
Basically, the known pleating and guide fence for turning the inner free edges next to the first joining seam of the material in the turned collar can be used, but its use in making the outer corner seam on the collar is made impossible by the fact that turning the collar around the corner seams with the sewing machine stopped and with the guide fence fitted is just as impossible as turning over those areas which had to be processed without the pleating fence. Therefore, there is no way in which ironing of the turned collar can be avoided.